Discuss the four main categories of internal and external influences on staffing decision making. Describe the differences among trend, ratio, and regression analysis methods for forecasting staffing needs, and when each might be most appropriate. Describe the differences among job requirements, competency-based, and job rewards analysis techniques, highlighting the strengths and weaknesses of each approach. Develop a competency-based model for an organization you are familiar with, starting from the mission and values and going down to a few specific job titles.